The purpose of this randomized, double-blind study is to investigate the efficacy and safety of NS229 compared with placebo over a 28-week study treatment period in subjects with Eosinophilic Granulomatosis with Polyangiitis (EGPA) receiving background corticosteroid therapy with or without Mepolizumab/Benralizumab therapy. During the treatment period corticosteroid dose will be tapered.
The key outcomes in the study focus on evaluation of clinical remission, defined as Birmingham Vasculitis Activity Score (BVAS)=0 with a corticosteroid dose of \<=4 mg/day prednisolone/prednisone.
